| 摘要 |
PROBLEM TO BE SOLVED: To encode an input voice containing a tone component much in high area with high efficiency by dividing the frequency area coefficient of an input signal sample to generate a coefficient small piece group, classifying the coefficient small pieces to a plurality of groups followed by flattening, and encoding them. SOLUTION: An input signal is converted to the coefficient of frequency area, and a series of coefficients are bundled every band of about 100 Hz width to form coefficient small pieces, and the respective coefficient small pieces are classified to a high level group and low level group according to the intensities. For example, when the magnitude of the coefficient of frequency area is fluctuated as in a modified discrete conversion (MDCT) coefficient, the adjacent coefficients are bundled to form coefficient small pieces, and the coefficient small pieces are classified to a small coefficient group G0 and a large coefficient group G1. After the group G1 with high intensity and the group G0 with low intensity are independently flattened, the two groups G0 and G1 are collected to one followed by vector quantization. |
